XRT Response Functions: effect of new atomic data (Chianti ver. 8.0, Sep-2015).

(27-May-2017, by Aki Takeda)

The XRT response functions were recalculated, in response to the release of new Chianti atomic database version 8.0. The new atomic database (Chianti 8.0) turned out to make only negligible change on the XRT response functions calclated with the previous versions of Chianti(ver. 7.1.3 and ver. 6.0.1). Note that we have changed the calibration of thicker filters since 2013, which gives 10-50% smaller response to the med-Al, med-Be, thick-Al, and thick-Be filters (for details, see previous page ). All the calculations here were performed with the new calibration parameters.

1. The Response functions.

The solar spectra were calculated with the latest Chianti version 8.0, for 'coronal' (sun_coronal_1992_feldman_ext.abund), 'hybrid' (sun_coronal_1999_fludra_ext.abund), and 'photospheric' (sun_photospheric_2007_grevesse.abund) abundances. Below are the previous versions for comparison. Then I modified XRT_FLUX.PRO so that it can access the above spectrum files by setting the corresponding keyword. Examples of usage are as follows (including older versions).

IDL> flux_c = xrt_flux800(logte, f1,f2, tim, /corona)
IDL> flux_h = xrt_flux800(logte, f1,f2, tim, /hybrid)
IDL> flux_p = xrt_flux800(logte, f1,f2, tim, /photos)
IDL> flux_c7 = xrt_flux713(logte, f1,f2, tim, /corona)
IDL> flux_h7 = xrt_flux713(logte, f1,f2, tim, /hybrid)
IDL> flux_p6 = xrt_flux601(logte, f1,f2, tim, /photos)
IDL> flux_cal1 = xrt_flux800(logte, f1,f2, tim, /corona, cal=1) ; old calibration

[ Example of calculating XRT response functions ]
For details, see the description of Mithra:/www/HINODE/XRT/xrt_ssw/xrt_flux800.pro.

IDL> tim='1-may-2017 00:00'                ; change as needed.
IDL> f1=0 & f2=2                            ; for Open/Ti-poly 
IDL> logte = 5.+findgen(61)*0.05            ; prepare a temperature array
IDL> flux = xrt_flux800(logte, f1,f2,  tim, /corona)

Below are the response functions of all the X-ray analysis filters available at XRT. It is known that the contamination accumulated on the CCD modifies the XRT response functions. As the amount of contamination varies with time, response functions are time-dependant. For the later convenience of analysis, the following response functions were calculated for the contamination level as of 12-Nov-2006.
Plots are clickable (i.e., click each plot to show more detailed info).

Al-poly/Openthin-Be/Open med-Be/Openmed-Al/Open
Open/Al-meshOpen/thick-Al Open/thick-BeAl-poly/Ti-poly

2. The Filter Ratios.

These plots shows that the Chianti ver 8.0.0 makes no sigificant difference in the filter ratio curves relative to those with version 7.1.3. On the other hand, recalibrated thick filters results in significant change in ratio curves (e.g., thick-Be/med-Al, thick-Be/thick-Al). Again, plots are clickable (i.e., click each plot to show more detailed info).

Al-poly/Al-meshthin-Be/Al-mesh thin-Be/Al-polymed-Be/Al-poly
med-Al/Al-polymed-Be/thin-Be med-Al/thin-Bemed-Al/med-Be

3. XRT_TEEM modification.

XRT_TEEM_CH800.PRO was prepared.

Instead of directly modifying XRT_TEEM, I made a wrapper procedure that sets up the arrays of specified solar spectrum, and passes them to XRT_TEEM. You can get it from Mithra:/www/HINODE/XRT/xrt_ssw (or Ylstone:/disk/yla/software/xrt_ssw).
IDL> XRT_TEEM_CH800, index1,data1,index2,data2,te,em, /corona
IDL> XRT_TEEM_CH800, index1,data1,index2,data2,te,em, /hybrid
IDL> XRT_TEEM_CH800, index1,data1,index2,data2,te,em, /photospheric
IDL> XRT_TEEM_CH800, index1,data1,index2,data2,te,em, solar_spectrum='./solar_spectrum/solspec_ch800_cr2012schmelz2_chianti.genx'

4. Newly introduced abundances.

A few of new photosperic abundance sets are newly introduced since the recent versions. For comparison, I calculated the following two sets. The comparison plots of the response functions with new and old hybrid abundances for the 5 filters as samples.